40C3: tours, schedule data, tour map and calendar entries

- tour-map shortcode: Leaflet map of the tour locations with routes from the
  Congress, from the map/tours sections of data/schedule/<event>.yaml; Leaflet
  and the OSMIC, Maki and Temaki icon sets vendored; 39C3 uMap data converted.
- calendar shortcode: per tour date, a pill with an .ics download (iCalendar)
  and a Google Calendar link; Font Awesome Free vendored, fa-icon partial.
- README sections for the calendar and tour map shortcodes and the map data.

assets/vendor/icons/maki/rail-light.svg

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" id="rail-light" xmlns="http://www.w3.org/2000/svg" width="15" height="15" viewBox="0 0 15 15">
+  <path id="path14245" d="M5.5,0C5,0,5,0.5,5,0.5v1C5,1.777,5.223,2,5.5,2S6,1.777,6,1.5V1h1v2H6c0,0-2,0-2,2v3c0,3,3,3,3,3h1&#xA;&#x9;c0,0,3,0,3-3V5c0-2-2-2-2-2H8V1h1v0.5C9,1.777,9.223,2,9.5,2S10,1.777,10,1.5v-1C10,0,9.5,0,9.5,0H5.5z M7.5,4l2.0449,0.7734L10,6.5&#xA;&#x9;C10.1316,7,9.5,7,9.5,7h-4c0,0-0.6316,0-0.5-0.5l0.4551-1.7266L7.5,4z M7.5,8C7.7761,8,8,8.2239,8,8.5S7.7761,9,7.5,9&#xA;&#x9;S7,8.7761,7,8.5S7.2239,8,7.5,8z M4.125,12L3,15h1.5l0.375-1h5.25l0.375,1H12l-1.125-3h-1.5l0.375,1h-4.5l0.375-1H4.125z"/>
+</svg>